Researches supported by Key National Natural Science Foundation China's answer to Minamata Convention To reveal the characteristics of speciated atmospheric mercury concentrations (TGM, Hg(II) and Hg(p)) in the offshore area, west Pacific Ocean China is the largest contributor of anthropogenic mercury emission in the world, mercury pollution has become a serious environmental problem. Atmospheric mercury monitoring started just in recent years in China, the lack of monitoring data in background sites and data of speciated atmospheric mercury greatly restrains the study of mercury pollution of China. In this study, different species of atmospheric mercury were observed, which is very important to the study of mercury's transport and fate in China.